There are various types of connections or joints comprising a metallic screw or bolt to be screwed into a plastic part. The plastic part has a bore having a diameter which, for example, approximately similar to the pitch diameter of the screw threads. The screw threads of the screw or bolt are of such a structure that they form threads within the plastic part by displacing material or by a tapping or cutting operation.
Conventional connections or joints--no matter whether the screw threads are of the single, double or multiple thread type--suffer from the drawback that the screw when being positioned upon the plastic part is oriented obliquely to the axis of the bore corresponding to the pitch angle of the threads. It is difficult to screw or thread the bolt or screw into the bore under substantial axial pressure. Furthermore there is the risk that the screw or bolt will be screwed into the bore in an oblique manner when the axis of the screw or bolt is inclined with respect to the axis of the bore. Still further, when a screw or bolt is screwed into the bore again there will be the risk that it will form additional threads in the bore so as to weaken the connection or joint.